Nanoimprinting is known as a technique of forming fine patterns at low cost. The nanoimprinting is a method of pressing a template having concaves and convexities, which correspond to a pattern to be formed on a substrate, onto a curable organic material layer applied on the substrate surface, followed by radiation, heating, etc. to harden the curable organic material, and separating the template from the curable organic material layer, thereby transferring the pattern onto the substrate. If there are defects on the template surface, the defects are also transferred onto the substrate surface. For this reason, defect inspection is performed on the template or the transferred pattern.
In recent years, with increase in degree of integration of semiconductor devices, microfabrication has progressed for the size of each device and the width of wirings, gates, etc. that constitute each device. For example, a half pitch (expressed as an hp, hereinafter), which is half of a line-and-space pattern, has become smaller than 100 nm. For this reason, defect inspection is required to detect extremely small pattern defects. A known defect inspection method is to detect micro defects by using a short wavelength laser as a light source. There are other known inspection equipment and method which are capable of highly accurate inspection with a minimum decrease in intensity of inspection light, by using linearly polarized light as the inspection light and adopting an optical system having a polarization beam splitter. However, the known inspection equipment and method have a difficulty in accurate detection of micro defects due to optical resolution limits and the like.